Stereos. They were almost as ubiquitous as fire extinguishers in a student's room. Just about everyone had one. And roaches (everyone had many, many more than one).
Stereos provided our high-fidelity musical entertainment. Today's systems are quite different from what we had in the '70s. Whereas today's units are indeed a unit (receiver, amplifier, tape deck, CD player and sometimes even speakers in a single plastic body), high fidelity in the '70s was built on components (and Bang & Olufsons are still built on that principle today). You didn't buy everything in one box (well, you could, but the sound reproduction was, well, Heathkit quality). No, you bought everything separately - receiver, amplifier (most receivers were the amplifier, but a really sophisticated set-up required a separate amplifier to really give the sound a boost), speakers and a turntable. Those with the money would get a cassette tape player to go with the system, but frequently the turntable was all you needed, especially in the days of 33 1/3 long-playing records. I later found the tape player to be a useful feature because I liked to rip my music off the radio, and somehow recording the ambient sound coming through the air tended to lose something - and gain something (like a coughing fit in the middle of a song you were recording). Connecting it all together were jacks and wires, and you had to plug the right jack into the right hole, otherwise you wouldn't get sound to your speakers. It was red jack to red hole, black jack to black hole, and so on. It was a little like trying to patch together all the components of a desktop computer (but who uses those anymore?)
In the '60s, stereo receivers would frequently come from places like RadioShack. My father, the Renaissance Man, actually brought home a kit from RadioShack and carefully soldered the whole thing together, giving us our first stereo system. When I bought my first system, in 1977, I carefully researched Consumer Reports (my high-brow neighbors on the floor went for the electronics magazines with the reports on stereo equipment that were prepared by experts in the field, supposedly), and developed a plan for a system with everything I needed for about $400. In those days, $400 would buy you about 100 watts of power, a turntable with a clean sound coming through the tone arm and needle, and a set of speakers that could faithfully reproduce just about anything recorded on Deutsche Gramophon. I went with a Harman Kardon receiver/amplifier, a B-I-C turntable with an AudioTechnica cartridge and needle on the tone arm and Avid speakers - all of which came highly recommended by Consumer Reports. It was plenty powerful; in fact I could stick my speakers into the window and bounce an echo off the Landau Building (a Chemical Engineering lab right next to East Campus) from my Goodale dorm room.
As powerful as my system was (and it had enough power to blast Hoyt Axton's "You're the Hangnail in My Life" clear up Ames Street), it was no match for Norm Sheppard's system with its floor-mounted speakers. Ed, our hall tutor, also had a massive sound system that was just perfect for listening to the heartbeat at the end of Pink Floyd's "Dark Side of the Moon" broadcast at 100 decibels. Various people on Third and Fourth East also had the ability to crank it up and annoy those peaceful souls on First West, and when it was time for a party, we could string all the stereos together in parallel so that they'd all play the same record in unison. Of course, doing that would blow all the fuses, so we simply removed them and stuffed a large wad of aluminum foil into the fuse socket. When we cranked up the sound, the foundations of West Campus literally moved.
When I became a disc jockey (and I was the house DJ for a few of the Strat's Rats in my senior year), I found out about different types of turntables. The set-up in my dorm room had a belt-drive turntable, which was typical for most consumer applications, but disc jockeys needed something more heavy-duty. For them, there were direct-drive turntables, in which a gear in the base of the unit spun the turntable, rather than a belt. This was essential because disc jockeys, whether in a broadcast studio or a night club, needed the ability to cue records by hand so that the music started the instant the needle was placed on the record (there were little tricks to this; you could let the turntable spin while holding the record in place on the felt pad that was the turntable top, then gently releasing the record so that it would start to spin without the needle skipping). Belt drives were too jerky and unreliable for this task; for one thing, holding the record still could screw up the belt, and even if that weren't a problem, the jerk of the record when the belt engaged could cause the needle to skip off the disc. In the early '80s, Grandmaster Flash would learn how to slide records back and forth on a direct drive turntable, producing the "scratching" sound that has become so familiar to hip-hop enthusiasts.
As I mentioned, I did not buy a tape player for my stereo system until a few years later. I had acquired a car with a cassette player in it, and I wanted to record my LP's (and certain songs I heard on the radio) onto cassette tape so I could play them in my car. The first tape players had a single slot, or "deck", for the cassette tape, which meant that they recorded from either the turntable or the radio, then played back. There was no cutting and pasting possible; you got only what you recorded directly off the other units. Then, in the early-to-mid '80s, the first dual tape decks appeared...and the recording industry had a cow. "These dual decks will lead to music piracy" they screamed in unison, and the din got even louder when Aiwa made a dual dubbing deck that could record from one cassette to another at high speed. There were dire predictions of lost sales and attempts to restrict the use of the dual decks, but eventually, common sense and the consumer won out. The next threat was just about to emerge - the dual deck VCR, capable of dubbing from one VHS tape onto another. This was 1990. Within 20 years, everyone was loading MP3's onto their iPod's and Smartphones, and the music industry would never be the same again.